Air spring



v. v. VAN NATTAN Er AL AIR SPRING Fil-ladV July 151. 1923 lmlllhi lllmlllmm Patented Qct. 20, 1925.

UNITED @STATES PATENT ortica vrinLn v. VAN NATT'AN Ann CARLTON n. Gir-AY, orsnn FnANorsed-'cnmronnrng Ain srnrno,

Appncaeonmea July 11, 1923. seria-1 No. `650,859.1.

To aZZ'wwm t may concern: I

Be it known that we, VERLE V. VAN NAT- 'rAN andvv C'AnL'roN R. GRAY, eiti-zensof the United States, and residents of the city and county of San Francisco, State of California, have made a new and useful inventiontoy wit, Improvements in Air Springs; and, we do hereby declare the following to be a full, clear, concise, and exact description` of the same.

rIghis invention relates particularly to a hydro-pneumatic cushioning device more particularly known as an air spring, adaptable to use on vehicles, such as automobiles, wagons, trucks, buses and the like.

An object of the invention'` is to provide an air spring adapted tobe used as a cushioning element between relatively movable and immovable bodies for the purpose of obtaining resilient supportv and otherwise` functioning in the same manner as, and possessing. all of the conventional features of, shock absorbersandl steel springs.

A. further-object of the invention is to pro;- vide an` air spring so' constructedy as to' avoid reference or similarity in operation and structure to conventional types of automobile springs formed of telescoping tu.- bular members of which one member is securedI to an automobile frame and the sliding member tothe vehicle spring.

A still further object of the invention is to provide an air spring that will be superior in point of simplicity andv inexpensivenessA of construction, positiveness ofV operation, facility and convenience in use and general efficiency as contrasted with devices and mechanisms of a similar character. Other objects and advantages will appear as this descriptionV progresses.

In this specification andv the annexed drawings, the invention is illustrated inthe form considered: to be the best, but it is to belunderstoodthatthe invention is not limited to suchv form, because it= may boem- 'bodied in other forms, and it isalso to'be understood that in and by the claims following the; description, it is desiredto cover the invention in whatsoever form it maybe embodied; y In thev accompanying-one sheet ofldraw'- lugs' lrrepresents avertical section through an air spring constructed in?y accordance with my invention.-`

Fig. 2 is a side elevation FigQl partly? brokenl away on the line 2-2. l n

Fig.,` 3 isfa section taken through 12 on the line` 3 3, i y

Fig. 4: is a plan and. cross-sectional. View of the. flan-ged ring for spreadi-ng` the cup leather onthe piston. A. C 1' 'I Fig. 5 is a plan view and side elevation of the,y expander plate. used i-ncon-junction with the flanged ring. y n lVarious` types of: hydro-pneumatic. and .air cushioning devices have-,been inventedforA achieving resi-lienty efectsbetween movable and immovable bodies, all. of ,whichy usually employ, as essential parts of the construetion, either internalv compression pumps, pressure valves, telescoping cylinders;L dashl. pots, coil springs, air pum-ps,y or'the like.; The presen-t invention, as well'zasthatillustrated and described incur pending applicationbearing Ser. No; 459,603 and filed!4 onK April 8, 1921-, differ from the conventional type-of airspring` inl so far as-the ingenious mechanisms, referred to, have -been eliminated, andl a device capable of functioning in substantially the same mannen, with. a; materially reduced numberofparts,l hasbeenproduced. o

detail' the construction illustrated in the drawings comprisesthe f'rame'l-of an-:alrtomobile,-,or other equivalent .stationary element. Anl air cushioning device consisting: of' a housing 2 is' bolted to the stationary element l bythe bolts 3 and has ar guide frame-4 depending from` theV lower side of* said housing. Theupperface of. thehousingis vprovidedy with a circular projection 5 thereon, theoutsideofwhich is threaded' to receive the internally threadedA bottom ofa cylinderf. The end ofthefcylindery is ,closed at-l 6`. and has an: a'ir' valve'` 7 detachabl-yr` mounted'A therein, and covered by a cap 8, for excluding dirt andr dnst from the said' valve andifor preventing pressure losses; from said valve.l Jlthofugh I haveshownandgdescribedr the cylinder 6- as being. provided with' a closedA end 6" formedintegrally with the said'fcyl-inder l6, it w-ouldfbeclearlyfwithin." the punview. of; this: inventionfzto detachably connect the closed end of the cylinder; `to the cylinder proper:

A bearing: 9` isf provided: cx'nfrcentrically-` throughr the. circular `projectionv;and@ lions-f 1 ingQ',y which .-bearingiii's inr axialfregistryvwfitln the' axis ofthecylindend ThesaXis-sofgtliei by the kscrews 13 over the outside face of the guideway 4 to the depending portion of the housing Y A slide member or block 14 is slidably con-f inedto movement in a vertical direction in the recess 12 provided between thecover 11 extension.

and depending member 4. The slide shoe 14 has a central projection 15 thereon which extends through the slot 1() in the member 4. The projection 15 is slotted at 16 to register with a cavity 17 formed in said slide shoe The extension 15 is drilled transversely to receive a shackle bolt 18, the

,opposite ends 'ofV which have the shackle plates'19'and 2O mounted thereon, and between which the leaf spring 2]. is pivotally mounted on the pin 22, Y l

A piston member is'reciprocatingly mountedwithin the cylinder 6, consisting of a pair of circula-r plates 23 and 24 on the upper faces of which the cup'leathers25 and 26 respectively, are mounted. Annular flanged rings 27 and 28 are adapted to Contact with the up-turned edges of the cup leathers 25 and 26 to force the edges outwardly into contact with the cylinder wall. Expander plates 29 and 30 are utilized to press against the .flanged rings 27 and 28 and create the desired tensional contact on the cup leathers 25 and 26. The assembly of circular plates, cup leathers, flanged rings and expander plates, is securely mounted `on the reduced threaded end 31 of a connecting rod 32, by means of a nut 33. The connecting rod 32 is adapted to move axially within the cylinder 6, being` slidably confined inthe bearing 9, provided through the upper face of the housing 2. The lower end of the connecting rod 32 is reduced at 35, adjacent the enlarged end 3670i said connecting rod, for the purpose of being detachably engaged with the slot' 16 and cavity 17 formed in the extension 15 of the cylinder shoe 14. The connecting` rod 32 is slotted at 37 on its exterior for substantially the full length thereof to provide avent or bleeder port into ther space between the underside ot' the piston and the upper face of the housing 2, and thus prevent the forming of a partial vacuum or anyY retarding suction effects in said space on the 11p-stroke of the cylinder piston. 1 y y The invention operates in the vollowin Y manner. Air is passed through the valve into the space provided between the upper face ofthe piston and the closed end of the Zylinder, until `a predetermined and desired pressure has been obtained. The pressure p lubricating the same and for hermetically sealing against air pressure losses. Movement' of the relatively movable leaf spring 21 would be transmitted through the shackle plate 19 and 2() to the slide shoe 14, which in turn would be moved vertically in the guide frame 4. Movement of the slide shoe 14V would be thus transmitted through the c0nnecting rod 32 and piston against the air pressure contained in the upper end `of the cylinder 6 and all shocks vand similarl dis-y ruptive effects absorbed. No air pressure is maintained between the underside of' the` piston and the upper face of the housing 2, but means is provided' for partially exhausting air compressedin said space by the downward movementof the piston. The air or' normal pressureA which would be compressed in said lower space on the downward stroke o the piston would be vented to the atmosphere through the slot 37 and sims ilarly atmospheric air would be permitted to pass through said slot into said space to fill the same whereby to allow thel piston to move freely without any retarding effects which would be produced were the 'suction or partial vacuum in said space not compen sated for. On the recoil, the air that is compressed by the underside of the piston effectively cushions any downward movement thereof somewhat similar to the cushioning effect obtained by the air pressure in the upper end of the cylinder.

Having thus described this invention, what I claim and desire to secure by Letters Patent is:

1. A cushioning device comprising a closed cylinder iixed toa vehicle frame and adapted to contain a pressure; a substantially closed guide frame depending 'from and connected to said cylinder; a piston slidably retained within said cylinder; a slide, slidably retained in said guide. irame; a connecting rod extending through an end of said cylinder and pivota-lly connected at its opposite ends to said piston and slide; and a movable` vehicle springconnected to said slide and adapted to move said interconnected slide and piston axially with respect to said cylinder and guideI frame.

2. A cushioning device comprising a closed cylinder fixed to a vehicle frame and adapted to contain a pressure; a substantially closed guide frame depending from and oH'set relative to the axis of said cylinder;` a piston slidably retained within said cylinder; a slide, having an end slidably guided in and movable in said guide frame` on a slide path parallel with the axis of said cylinder; a connecting rod extending all through an end of said cylinder and pivotally connected at its opposite ends to said piston and slide; and a vehicle spring connected to said slide and adapted to move the same.

3. A cushioning device comprising a closed cylinder fixed to a vehicle frame and adapted to contain a pressure; a substantially closed guide trame off-set relative to, depending from and independent of said cylinder; a piston slidably retained within said cylinder; a connecting rod secured to said piston and extending axially from said cylinder; a block, movable on a slide path parallel to the axis of said cylinder, in said guide trame and loosely connected to said rod; and a vehicle spring connected to said block and adapted to move the saine.

4. A cushioning device comprising a closed cylinder iiXed to a vehicle trame and having a piston slidably retained therein and adapted to contain a relatively constant pressure between one side of said piston and an end o said cylinder; a guide frame7 off-set relative to and secured to said cylinder; a T shaped block; slidably mounted in said guide frame and movable on a slide path parallel with the axis of said cylinder, loosely connected t0 said piston; a vehicle spring adapted to be connected to said block to move the same against said pressure; and means tor confining a variable pressure between the opposite sides of said piston and the opposite wall ot said cylinder.

5. A cushioning device comprising a closed cylinder iiXed to a vehicle trame and having a piston slidably retained therein and adapted to contain a relatively constant pressure between one side of said piston and an end of said cylinder; a connecting rod secured to said piston and extending trom said cylinder; a guide trame securedv to said cylinder and ott-set substantially parallel with the axis of said cylinder; a T block slidably mounted in said guide, movable with respect to said cylinder and loosely connected to said rod; a vehicle spring adapted to be connected to said T block; to move the same against said pressure; and means for confining a variable pressure between the opposite side of said piston and the opposite wall of said cylinder.

6. A cushioning device comprising a relatively stationary closed cylinder adapted to be fixed to a vehicle trame; a separate T l shaped guide frame on said cylinder; a piston slidably retained in said cylinder and adapted to confine a relatively constant pressure between one side thereof and an end of' said cylinder; means for retaining a varable pressure between the other side vof said piston and the end of said cylinder; a T shaped member slidably retained in said guide frame and having a projection thereon oscillatably connected with said piston and a relatively movable means on said vehicle secured to said T shaped member.

7. A cushioning device comprising a relatively stationary closed cylinder adapted to be iXed to a vehicle traine; a separate and substantially closed guide frame, including separate end guides, depending from said cylinder; a piston and rod slidably guided in said cylinder, said piston being adapted to confine a substantially constant pressure between one :face of it and the cylinder end, and a variable pressure between its opposite face and the opposite end of the said cylinder; a block, slidably retained in said guide frame, having a slotted portion therein adapted to be detachably and loosely connected to the end ot said piston rod and a relatively movable vehicle spring means secured to and adapted to move said block.

8. An air spring cushioning device such as described comprising a closed cylinder adapted to be pivotally mounted on a relatively stationary eleinent; a separate and substantially closed guide frame dependingV from said cylinder and off-set relative to the axis of said cylinder; a piston and rod slid-v ably guided in said cylinder, said piston being adapted to conne a substantially constant pressure between one tace of it and the cylinder end and a variable pressure between its opposite face and the opposite end of the said cylinder; al block, slidably retained in said off-set guide frame7 having a slotted portion therein adapted to be detachably and loosely connected with said piston rod and movable therewith and a relatively mov-r able vehicle spring secured to said block.

ln testimony whereof; we have hereunto set our hands at San Francisco; California, this 28rd day of June, 1923.y

VERLE V. VAN NATTAN. CARLTON R. GRAY. 

